1. Field of the Invention
This invention relates to physiological monitoring and recording devices, and in particular to telemetric forms of such devices.
2. Description of the Prior Art
Conventionally, the monitoring of a patient such as in an intensive care unit of a hospital has required vigilant surveillance by one or more nurses. More recently, monitoring means have been utilized in the form of electrical monitoring and recording devices which are connected to the patient by suitable electrical wires. Such conventional devices have required that the patient's bed be made electrically shockproof and it has been found that to suitably shockproof such a hospital bed costs approximately $2,500.00. Notwithstanding such expensive shockproofing, a number of patients have died each year as a result of electric shock because of failure of the system.
The use of such wiring limits the mobility of the patient and conventionally has required that the patient remain in the shockproof bed.
Because of the high cost of the equipment and the installation, the use thereof has been primarily limited to intensive care units of hospitals and, thus, such monitoring has not been readily available in connection with less serious patient problems.
It has been known in the prior art to use telemetric devices in connection with physiologic monitoring. One such device is shown in the Preston U.S. letters Pat. No. 3,212,496 which discloses a molecular physiological monitoring system wherein the voltage produced by the heart in the functioning thereof in sensed and transmitted to an EKG receiver and recording or display device. In Preston, the transducer system is implanted subcutaneously or externally.
Other patents which show different forms of transducers and telemetric physiological devices are shown in the U.S. letters Patent 2,958,781 Marchal et al Radio-Physiological Method and Means 3,144,017 Muth Pill-Type Swallowable Transmitter 3,190,285 Muth Construction of a Battery Electrode for an Endo- Radiosonde 3,343,528 Kirkham Electrocardiographic Switching System 3,555,529 Brown et al Apparatus for Measuring Electric Field Radiation from Living Bodies 3,572,316 Vogelman et al Physiological Signal Monitoring System 3,583,392 Frieberger Method of Recording Recurring Events.